1. Field of the Invention
The present invention relates to a process for the on-demand production of small quantities of lead azide. In particular, the present invention relates to a process for the on-demand production of small quantities of lead azide, said process comprising the steps of:
in a reactor assembly,
introducing a metered quantity of an azide component comprising sodium azide solution and a metered quantity of a lead component comprising a solution of a lead salt sufficient to react with said azide component into a primary mixing chamber that may be in the form of a T-mixer or Y-mixer;
conveying said azide component and said lead component into a static mixer;
permitting said azide component and said lead component to react together, forming insoluble crystals of lead azide as a slurry in an aqueous medium; and,
separating said lead azide crystals from said aqueous medium,
wherein the process is carried out within at least one explosion-proof chamber.
2. Description of Related Art
Lead azide remains a required component in the detonation, and the detonators, of nearly every type of munitions. Unfortunately, however, lead azide is no longer produced in the United States. The Department of the Army's existing stockpile of lead azide is stored at Lone Star AAP. A recent study showed that the material could recrystallize under long-term storage conditions, causing potentially dangerous changes in sensitivity and performance. Recent analyses of samples of stockpiled lead azide have identified batches with such modified crystals.
Traditional commercial production of lead azide has required stainless steel mixing kettles, air-driven agitation, and safety barricades in a dedicated facility, with all the capital costs, which are attendant to such requirements. Commercial production is typically carried out in a batch process, with a typical production being three and a half kilograms (3.5 kg) in a sixty-liter (60L) stainless steel kettle. Production is based upon simple chemistry in which an aqueous solution of a lead salt, typically lead (II) acetate or nitrate, is mixed with an aqueous solution of sodium azide. The reaction is essentially instantaneous, and the lead azide product precipitates out.
Because lead azide is so unstable, however, and because other metal azides can result that are even more unstable, the manufacturing process is dangerous. Further, the presence of lead, a heavy metal, creates environmental risks and regulatory issues.